About 15 years ago, I made a 2' x 12' long darkroom sink for my Black and White Photography lab at home, and I used West Epoxy because my sailboating friend told me that if I used Polyurethane sealer, he would never let me on his boat again! Needless to say, I am very happy with the results with the epoxy finish.

I place my mugs into the dishwasher rack tilted so water won't collect. After a few months of reminding my wife... well, she refuses to load the dishwasher now and just makes me do it.

I know what drfrank is referring to, and tilting them may not completely solve the problem since many mugs have deep concave shapes on their bottoms. I think I'd just put some epoxy in the mug bottoms and let them sit as they may in the dishwasher. Its a one-time placement vs a lifetime of loading the dishwasher!

edit: PS: when you fill the base with epoxy, make sure you leave it with a slight concave meniscus. If not, you will have mugs that will be a little tipsy and rattle as they stand on the table and will require sanding to correct the situation.

Last edited by GaryProtein on Wed Mar 05, 2008 1:25 pm; edited 1 time in total

Yeah, it slipped my mind that there are mugs with deep cavities. The mugs that I own that give me trouble are only 3-4 mm deep, so the tilt method works. Any deeper and it would be indeed be a problem.

there is of course the most obvious solution - works with deep and shallow bottom depressions:

drill a hole for drainage

Is this a joke?? Do you mean to drill all the way through the base so the underside concavity is contiguous with the inside of the mug for drainage, thereby violating the integrity of the mug? Sorry, but I couldn't picture anything else. Maybe I am missing something.

About 15 years ago, I made a 2' x 12' long darkroom sink for my Black and White Photography lab at home, and I used West Epoxy because my sailboating friend told me that if I used Polyurethane sealer, he would never let me on his boat again! Needless to say, I am very happy with the results with the epoxy finish.

edit: I was writing while DrBiggles was posting.

Tee hee, yeah.

The polyurethane finish would have probably survived just fine. True isocyanate cured (2 component) polyurethanes don't do well when submersed for anything longer than 2 weeks. If it has a chance to dry from day to day, you're fine. But this is only if it was a true Linear Polyurethane. One can walk in to any damned hardware store or marine chandlery and buy stuff with words all over the darned cans. The semi-new word is Acrylic, a part of the ester group (breaks down on exposure to moisture). Lousy cheap crap that manufacturers add to lower the price of their product.

The West System is okay for what it's good for. New boat construction and things that don't move. Once cured, it's brittle. Pour some on a polyethylene sheeting and let it cure in a disc. Once cured, snap it. No bendy. It develops an amine blush that needs to be removed with a sudsy amonia wash or sanding. The pot-life is pretty darned short, 25 minutes or so, depending upon ambient temperature. This stuff can and is bought in bulk, repackaged and sold. Truly about as special as dirt. So many companies are doing the same with some modifications. Oh, and you want to have some real fun? Mix a few gallons together and watch the thermal runaway! Lousy crap.

It may or may not last in the butt of a drinking glass. If it hit the dishwasher I'd say your days were numbered. Handwash? Forever. Oh, and don't forget to chemically etch the glass for excellent adhesion, just sayin'.

The West System is okay for what it's good for. New boat construction and things that don't move. Once cured, it's brittle. Pour some on a polyethylene sheeting and let it cure in a disc. Once cured, snap it. No bendy. It develops an amine blush that needs to be removed with a sudsy amonia wash or sanding. The pot-life is pretty darned short, 25 minutes or so, depending upon ambient temperature. This stuff can and is bought in bulk, repackaged and sold. Truly about as special as dirt. So many companies are doing the same with some modifications. Oh, and you want to have some real fun? Mix a few gallons together and watch the thermal runaway! Lousy crap.

It may or may not last in the butt of a drinking glass. If it hit the dishwasher I'd say your days were numbered. Handwash? Forever. Oh, and don't forget to chemically etch the glass for excellent adhesion, just sayin'.

Biggles

Last I checked, most ceramic or glass mugs had a pretty high modulus of elasticity so I don't think flexing off the epoxy would be a problem. As far as pot life is concerned, once you mix the stuff, how many seconds does it tale to pour an ounce into the underside of as mug? Even if you're very compulsive, it couldn't take more than 20 seconds each. A pot life of 20 minutes would give enough time to pour more mugs than the typical person owns. Furthermore, you don't have to do them all from the same mixed pot. I think epoxy sticks pretty well to glass surfaces and even better to bisque (unglazed) porcelain/pottery, so other than cleaning the surface well, the epoxy should stay attached for probably the lifetime of the mug. The amber blush of the epoxy also shouldn't be as problem on the underside of the mug.

WE NEED A TESTER!

As an alternative to the epoxy, I now offer the suggestion of using RTV low viscosity silicone. Just clean the mug, squeeze it out of the tube and flow it on the underside of the mug. Silicone sticks VERY well to glass and ceramics and from personal experience, I can say definitely survives dishwashers.

The West System is okay for what it's good for. New boat construction and things that don't move. Once cured, it's brittle. Pour some on a polyethylene sheeting and let it cure in a disc. Once cured, snap it. No bendy. It develops an amine blush that needs to be removed with a sudsy amonia wash or sanding. The pot-life is pretty darned short, 25 minutes or so, depending upon ambient temperature. This stuff can and is bought in bulk, repackaged and sold. Truly about as special as dirt. So many companies are doing the same with some modifications. Oh, and you want to have some real fun? Mix a few gallons together and watch the thermal runaway! Lousy crap.

It may or may not last in the butt of a drinking glass. If it hit the dishwasher I'd say your days were numbered. Handwash? Forever. Oh, and don't forget to chemically etch the glass for excellent adhesion, just sayin'.

Biggles

Last I checked, most ceramic or glass mugs had a pretty high modulus of elasticity so I don't think flexing off the epoxy would be a problem. As far as pot life is concerned, once you mix the stuff, how many seconds does it tale to pour an ounce into the underside of as mug? Even if you're very compulsive, it couldn't take more than 20 seconds each. A pot life of 20 minutes would give enough time to pour more mugs than the typical person owns. Furthermore, you don't have to do them all from the same mixed pot. I think epoxy sticks pretty well to glass surfaces and even better to bisque (unglazed) porcelain/pottery, so other than cleaning the surface well, the epoxy should stay attached for probably the lifetime of the mug. The amber blush of the epoxy also shouldn't be as problem on the underside of the mug.

Generally speaking, epoxies pour like cold honey. It doesn't pour all that well and when monkeyed with gets strands like gooey cheese. Without halfway decent technique, it'd take a bit of time to make it look right. All the while the stuff you paid for is cooking off. Remember to count mixing time with your pot life. Epoxies don't stick to unprepped (molecularly smooth) glass and last.

And something I thought about this morning was how hot does the elecctric element in the dishwasher get to? Epoxy starts to soften and fail at 140 to 150 degrees F. I think your rtv idea would be a better solution. Except I'm not sure I want to look at rtv through my glass. We've got pallet loads of expired stuff at work. I'll see what I can find.

Biggles

PS - Hmm, I wonder if 2 component polysulfide rubber wouldn't do the job? We make a black version that might look pretty cool, it's stable for umpteen years.

What we need a high temperature epoxy with additives for adhesion and thermal expansion. One that's rated to be used around the preparation of food. RTV ain't going to work cause it'll cause, it's stinky and will cause horrible flavors with everything that's washed with it.

My boss says we can order the epoxy and run tests on the additives, but it'll cost money. I'm done.